This class should be used only when the Audio sink feature is Enabled.
This class is used to return :
STWVCall : Instance of the call, if the call is started correctly.
CallError : Instance of CallError when the call is not started
in the case of play it contain the audio stream
the event of the audio sink
the instance of the call when the call is started successfully
in the case of fail of starting the call
the type of the object.
Used to log the object